Synthetic antigens for the detection of antibodies to hepatitis C virus

ABSTRACT

Peptide sequences are provided which are capable of mimicking proteins encoded by HCV for use as reagents for screening of blood and blood products for prior exposure to HCV. The peptides are at least 5 amino acids long and can be used in various specific assays for the detection of antibodies to HCV, for the detection of HCV antigens, or as immunogens.

This application is a division application Ser. No. 09/275,265, filed Mar. 23, 1999, now U.S. Pat. No. 6,287,761, which in turn is a continuation of Ser. No. 08/391,671 filed Feb. 21, 1995, now U.S. Pat. No. 5,922,532; which is a continuation of Ser. No. 07/920,286, filed Oct. 14, 1992, abandoned, which is a 371 of PCT/EP91/02409, filed Dec. 31, 1991, the entire content of each of which are hereby incorporated by reference in this application.

The implementation of systematic testing for hepatitis B virus (HBV) has been instrumental in eliminating this virus from the blood supply. Nevertheless, a significant number of post-transfusion hepatitis (PTH) cases still occur. These cases are generally attributable to non-A, non-B hepatitis (NANBH) virus(es), the diagnosis of which is usually made by exclusion of other viral markers.

The etiological agent responsible for a large proportion of these cases has recently been cloned (Choo, Q-L et al. Science (1988) 244:359-362) is and a first-generation antibody test developed (Kuo, G. et al. Science (1989) 244:362-364). The agent has been identified as a positive-stranded RNA virus, and the sequence of its genome has been partially determined. Studies suggest that this virus, referred to subsequently as hepatitis C virus (HCV), may be related to flaviviruses and pestiviruses. A portion of the genome of an HCV isolated from a chimpanzee (HCV_(CDC/CHI)) is disclosed in EPO 88310922.5. The coding sequences disclosed in this document do not include sequences originating from the 5′-end of the viral genome which code for putative structural proteins. Recently however, sequences derived from this region of the HCV genome have been published (Okamoto, H. et al., Japan J. Exp. Med. 60:167-177, 1990.). The amino acid sequences encoded by the Japanese clone HC-J1 were combined with the HCV_(CDC/CHI) sequences in a region where the two sequences overlap to generate the composite sequence depicted in FIG. 1. Specifically, the two sequences were joined at glycine₄₅₁. It should be emphasized that the numbering system used for the HCV amino acid sequence is not intended to be absolute since the existence of variant HCV strains harboring deletions or insertions is highly probable. Sequences corresponding to the 5′ end of the HCV genome have also recently been disclosed in EPO 90302866.0.

In order to detect potential carriers of HCV, it is necessary to have access to large amounts of viral proteins. In the case of HCV, there is currently no known method for culturing the virus, which precludes the use of virus-infected cultures as a source of viral antigens. The current first-generation antibody test makes use of a fusion protein containing a sequence of 363 amino acids encoded by the HCV genome. It was found that antibodies to this protein could be detected in 75 to 85% of chronic NANBH patients. In contrast, only approximately 15% of those patients who were in the acute phase of the disease, had antibodies which recognized this fusion protein (Kuo, G. et al. Science (1989) 244:362-364). The absence of suitable confirmatory tests, however, makes it difficult to verify these statistics. The seeming similarity between the HCV genome and that of flaviviruses makes it possible to predict the location of epitopes which are likely to be of diagnostic value. An analysis of the HCV genome reveals the presence of a continuous long open reading frame. Viral RNA is presumably translated into a long polyprotein which is subsequently cleaved by cellular and/or viral proteases. By analogy with, for example, Dengue virus, the viral structural proteins are presumed to be derived from the amino-terminal third of the viral polyprotein. At the present time, the precise sites at which the polyprotein is cleaved can only be surmised. Nevertheless, the structural proteins are likely to contain epitopes which would be useful for diagnostic purposes, both for the detection of antibodies as well as for raising antibodies which could subsequently be used for the detection of viral antigens. Similarly, domains of nonstructural proteins are also expected to contain epitopes of diagnostic value, even though these proteins are not found as structural components of virus particles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D show the amino acid sequences of the composite HCV_(HC-J1/CDC/CHI) (SEQ ID NO:23)

FIGS. 2A-2L show the anitbody binding to individual peptides and various mixtures in an ELISA assay. Coating combinations used for FIGS. 2A-2L are as follows:

1: IX, 2: XVIII, 3: I, 4: III, 5: V, 6: IX+XVIII, 7: I+XVIII, 8: I+III+IX, 9: I+III+V+XVIII, 10: I+III+V+IX, 11: I+III+IX+XVIII, 12: I+III+V+IX+XVIII.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

It is known that RNA viruses frequently exhibit a high rate of spontaneous mutation and, as such, it is to be expected that no two HCV isolates will be completely identical, even when derived from the same individual. For the purpose of this disclosure, a virus is considered to be the same or equivalent to HCV if it exhibits a global homology of 60 percent or more with the HCV_(HC-J1/CDC/CHI) composite sequence at the nucleic acid level and 70 percent at the amino acid level.

Peptides are described which immunologically minic proteins encoded by HCV. In order to accommodate strain-to-strain variations in sequence, conservative as well as non-conservative amino acid substitutions may be made. These will generally account for less than 35 percent of a specific sequence. It may be desirable in cases where a peptide corresponds to a region in the HCV polypeptide which is highly polymorphic, to vary one or more of the amino acids so as to better mimic the different epitopes of different viral strains.

The peptides of interest will include at least five, sometimes six, sometimes eight, sometimes twelve, usually fewer than about fifty, more usually fewer than about thirty-five, and preferably fewer than about twenty-five amino acids included within the sequence encoded by the HCV genome. In each instance, the peptide will preferably be as small as possible while still maintaining substantially all of the sensitivity of the larger peptide. It may also be desirable in certain instances to join two or more peptides together in one peptide structure.

It should be understood that the peptides described need not be identical to any particular HCV sequence, so long as the subject compounds are capable of providing for immunological competition with at least one strain of HCV. The peptides may therefore be subject to insertions, deletions, and conservative or non-conservative amino acid substitutions where such changes might provide for certain advantages in their use.

Substitutions which are considered conservative are those in which the chemical nature of the substitute is similar to that of the original amino acid. Combinations of amino acids which could be considered conservative are Gly, Ala; Asp, Glu; Asn, Gln; Val, Ile, Leu; Ser, Thr; Lys, Arg; and Phe, Tyr.

Furthermore, additional amino acids or chemical groups may be added to the amino- or carboxyl terminus for the purpose of creating a “linker arm” by which the peptide can conveniently be attached to a carrier. The linker arm will be at least one amino acid and may be as many as 60 amino acids but will most frequently be 1 to 10 amino acids. The nature of the attachment to a solid phase or carrier need not be covalent.

Natural amino acids such as cysteine, lysine, tyrosine, glutamic acid, or aspartic acid may be added to either the amino- or carboxyl terminus to provide functional groups for coupling to a solid phase or a carrier. However, other chemical groups such as, for example, biotin and thioglycolic acid, may be added to the termini which will endow the peptides with desired chemical or physical properties. The termini of the peptides may also be modified, for example, by N-terminal acetylation or terminal carboxy-amidation. The peptides of interest are described in relation to the composite amino acid sequence shown in FIG. 1. The amino acid sequences are given in the conventional and universally accepted three-letter code. In addition to the amino acids shown, other groups are defined as follows: Y is, for example, NH₂, one or more N-terminal amino acids, or other moieties added to facilitate coupling. Y may itself be modified by, for example, acetylation. Z is a bond, (an) amino acid(s), or (a) chemical group(s) which may be used for linking. X is intended to represent OH, NH₂, or a linkage involving either of these two groups.

Peptide I, shown in SEQ ID NO:1, corresponds to amino acids 1 to 20 and has the amino acid sequence:

(I)

Y-Met-Ser-Thr-Ile-Pro-Lys-Pro-Gln-Arg-Lys-Thr-Lys-Arg-Asn-Thr-Asn-Arg-Arg-Pro-Gln-Z-X.

Peptide I, shown in SEQ ID NO:1, corresponds to amino acids 7 to 26 and has the amino acid sequence:

(II)

Y-Pro-Gln-Arg-Lys-Thr-Lys-Arg-Asn-Thr-Asn-Arg-Arg-Pro-Gln-Asp-Val-Lys-Phe-Pro-Gly-Z-X.

Of particular interest is the oligopeptide IIA, shown in SEQ ID NO:3, which has the sequence

(IIA)

Y-Gln-Arg-Lys-Thr-Lys-Arg-Asn-Thr-Asn-Arg-Arg-Z-X.

Peptide III, shown in SEQ ID NO:4, corresponds to amino acids 13 to 32 and has the sequence:

(III)

Y-Arg-Asn-Thr-Asn-Arg-Arg-Pro-Gln-Asp-Val-Lys-Phe-Pro-Gly-Gly-Gly-Gln-Ile-Val-Gly-Z-X.

Peptide IV, shown in SEQ ID NO:5, corresponds to amino acid 37 to 56 and has the sequence:

(IV)

Y-Leu-Pro-Arg-Arg-Gly-Pro-Arg-Leu-Gly-Val-Arg-Ala-Thr-Arg-Lys-Thr-Ser-Glu-Arg-Ser-Z-X.

Peptide V, shown in SEQ ID NO:6, corresponds to amino acids 49 to 68 and has the sequence:

(V)

Y-Thr-Arg-Lys-Thr-Ser-Glu-Arg-Ser-Glu-Pro-Arg-Gly-Ara-Ara-Gln-Pro-Ile-Pro-Lys-Val-Z-X.

Peptide VI, shown in SEQ ID NO:7, corresponds to amino acid 61 to 80 and has the following sequence:

(VI)

Y-Arg-Arg-Gln-Pro-Ile-Pro-Lys-Val-Arg-Arg-Pro-Glu-Gly-Arg-Thr-Trp-Ala-Gln-Pro-Gly-Z-X.

Peptide VII, shown in SEQ ID NO:8, corresponds to amino acids 73 to 92 and has the sequence:

(VII)

Y-Gly-Arg-Thr-Trp-Ala-Gln-Pro-Gly-Tyr-Pro-Trp-Pro-Leu-Tyr-Gly-Asn-Glu-Gly-Cys-Gly-Z-X.

Peptide VIII, shown in SEQ ID NO:9, corresponds to amino acids 1688 to 1707 and has the sequence:

(VIII)

Y-Leu-Ser-Gly-Lys-Pro-Ala-Ile-Ile-Pro-Asp-Arg-Glu-Val-Leu-Tyr-Arg-Glu-Phe-Asp-Glu-Z-X.

Peptide IX, shown in SEQ ID NO:10, corresponds to amino acids 1694 to 1713 and has the sequence:

(IX)

Y-Ile-Ile-Pro-Asp-Arg-Glu-Val-Leu-Tyr-Arg-Glu-Phe-Asp-Glu-Met-Glu-Glu-Cys-Ser-Gln-Z-X.

Peptide X, shown in SEQ ID NO:11, corresponds to amino acids 1706 to 1725 and has the sequence:

(X)

Y-Asp-Glu-Met-Glu-Glu-Cys-Ser-Gln-His-Leu-Pro-Tyr-Ile-Glu-Gln-Gly-Met-Met-Leu-Ala-Z-X.

Peptide XI, shown in SEQ ID NO:12, corresponds to amino acids 1712 to 1731 and has the sequence:

(XI)

Y-Ser-Gln-His-Leu-Pro-Tyr-Ile-Glu-Gln-Gly-Met-Met-Leu-Ala-Glu-Gln-Phe-Lys-Gln-Lys-Z-X.

Peptide XII, shown in SEQ ID NO:13, corresponds to amino acids 1718 to 1737 and has the sequence:

(XII)

Y-Ile-Glu-Gln-Gly-Met-Met-Leu-Ala-Glu-Gln-Phe-Lys-Gln-Lys-Ala-Leu-Gly-Leu-Leu-Gln-Z-X.

Peptide XIII, shown in SEQ ID NO:14, corresponds to amino acids 1724 to 1743 and has the sequence:

(XIII)

Y-Leu-Ala-Glu-Gln-Phe-Lys-Gln-Lys-Ala-Leu-Gly-Leu-Leu-Gln-Thr-Ala-Ser-Arg-Gln-Ala-Z-X.

Peptide XIV, shown in SEQ ID NO:15, corresponds to amino acids 1730 to 1749 and has the sequence:

(XIV)

Y-Gln-Lys-Ala-Leu-Gly-Leu-Leu-Gln-Thr-Ala-Ser-Arg-Gln-Ala-Glu-Val-Ile-Ala-Pro-Ala-Z-Y.

Peptide XV, shown in SEQ ID NO:16, corresponds to amino acids 2263 to 2282 and has the sequence:

(XV)

Y-Glu-Asp-Glu-Arg-Glu-Ile-Ser-Val-Pro-Ala-Glu-Ile-Leu-Arg-Lys-Ser-Arg-Arg-Phe-Ala-Z-X.

Peptide XVI, shown in SEQ ID NO:17, corresponds to amino acids 2275 to 2284 and has the sequence:

(XVI)

Y-Leu-Arg-Lys-Ser-Arg-Arg-Phe-Ala-Gln-Ala-Leu-Pro-Val-Trp-Ala-Arg-Pro-Asp-Tyr-Asn-Z-X.

Peptide XVII, shown in SEQ ID NO:18, corresponds to amino acids 2287 to 2306 and has the sequence:

(XVII)

Y-Val-Trp-Ala-Arg-Pro-Asp-Tyr-Asn-Pro-Pro-Leu-Val-Glu-Thr-Trp-Lys-Lys-Pro-Asp-Tyr-Z-X.

Peptide XVIII, shown in SEQ ID NO:19, corresponds to amino acids 2299 to 2318 and has the sequence:

(XVIII)

Y-Glu-Thr-Trp-Lys-Lys-Pro-Asp-Tyr-Glu-Pro-Pro-Val-Val-His-Gly-Cys-Pro-Leu-Pro-Pro-Z-X.

Peptide XIX, shown in SEQ ID NO:20, corresponds to amino acids 2311 to 2330 and has the sequence:

(XIX)

Y-Val-His-Gly-Cys-Pro-Leu-Pro-Pro-Pro-Lys-Ser-Pro-Pro-Val-Pro-Pro-Pro-Arg-Lys-Lys-Z-X.

Of particular interest is the use of the mercapto-group of cysteines or thioglycolic acids used for acylating terminal amino groups for cyclizing the peptides or coupling two peptides together. The cyclization or coupling may occur via a single bond or may be accomplished using thiol-specific reagents to form a molecular bridge.

The peptides may be coupled to a soluble carrier for the purpose of either raising antibodies or facilitating the adsorption of the peptides to a solid phase. The nature of the carrier should be such that it has a molecular weight greater than 5000 and should not be recognized by antibodies in human serum. Generally, the carrier will be a protein. Proteins which are frequently used as carriers are keyhole limpet hemocyanin, bovine gamma globulin, bovine serum albumin, and poly-L-lysine.

There are many well described techniques for coupling peptides to carriers. The linkage may occur at the N-terminus, C-terminus or at an internal site in the peptide. The peptide may also be derivatized for coupling. Detailed descriptions of a wide variety of coupling procedures are given, for example, in Van Regenmortel, M. H. V., Briand, J. P., Muller, S., and Plaué, S., Laboratory Techniques in Biochemistry and Molecular Biology, Vol. 19, Synthetic Polypeptides as Antigens, Elsevier Press, Amsterdam, N.Y., Oxford, 1988.

The peptides may also be synthesized directly on an oligo-lysine core in which both the alpha as well as the epsilon-amino groups of lysines are used as growth points for the peptides. The number of lysines comprising the core is preferably 3 or 7. Additionally, a cysteine may be included near or at the C-terminus of the complex to facilitate the formation of homo- or heterodimers. The use of this technique has been amply illustrated for hepatitis B antigens (Tam, J. P., and Lu, Y-A., Proc. Natl. Acad. Sci. USA (1989) 86:9084-9088) as well as for a variety of other antigens (see Tam, J. P., Multiple Antigen Peptide System: A Novel Design for Synthetic Peptide Vaccine and Immunoassay, in Synthetic Peptides, Approaches to Biological Problems, Tam, J. P., and Kaiser, E. T., ed. Alan R. Liss Inc., New York, 1989).

Depending on their intended use, the peptides may be either labeled or unlabeled. Labels which may be employed may be of any type, such as enzymatic, chemical, fluorescent, luminescent, or radioactive. In addition, the peptides may be modified for binding to surfaces or solid phases, such as, for example, microtiter plates, nylon membranes, glass or plastic beads, and chromatographic supports such as cellulose, silica, or agarose. The methods by which peptides can be attached or bound to solid support or surface are well known to those versed in the art.

Of particular interest is the use of mixtures of peptides for the detection of antibodies specific for hepatitis C virus. Mixtures of peptides which are considered particularly advantageous are:

A. II, III, V, IX, and XVIII

B. I, II, V, IX, XI, XVI, and XVIII

C. II, III, IV, V, VII, XI, XVI, and XVIII

D. II, IX, and XVIII

E. II, III, IV, and V

F. VIII, IX, XI, XIII, and XIV

G. XV, XVI, XVII, XVIII, and XIX

Antibodies which recognize the peptides can be detected in a variety of ways. A preferred method of detection is the enzyme-lined immunosorbant assay (ELISA) in which a peptide or mixture of peptides is bound to a solid support. In most cases, this will be a microtiter plate but may in principle be any sort of insoluble solid phase. A suitable dilution or dilutions of serum or other body fluid to be tested is brought into contact with the solid phase to which the peptide is bound. The incubation is carried out for a time necessary to allow the binding reaction to occur. Subsequently, unbound components are removed by washing the solid phase. The detection of immune complexes is achieved using antibodies which specifically bind to human immunoglobulins, and which have been labeled with an enzyme, preferably but not limited to either horseradish peroxidase, alkaline phosphatase, or beta-galactosidase, which is capable of converting a colorless or nearly colorless substrate or co-substrate into a highly colored product or a product capable of forming a colored complex with a chromogen. Alternatively, the detection system may employ an enzyme which, in the presence of the proper substrate(s), emits light. The amount of product formed is detected either visually, spectrophotometrically, electrochemically, or luminometrically, and is compared to a similarly treated control. The detection system may also employ radioactively labeled antibodies, in which case the amount of immune complex is quantified by scintillation counting or gamma counting.

Other detection systems which may be used include those based on the use of protein A derived from Staphylococcus aureus Cowan strain I, protein G from group C Staphylococcus sp. (strain 26RP66), or systems which make use of the high affinity biotin-avidin or streptavidin binding reaction.

Antibodies raised to carrier-bound peptides can also be used in conjunction with labeled peptides for the detection of antibodies present in serum or other body fluids by competition assay. In this case, antibodies raised to carrier-bound peptides are attached to a solid support which may be, for example, a plastic bead or a plastic tube. Labeled peptide is then mixed with suitable dilutions of the fluid to be tested and this mixture is subsequently brought into contact with the antibody bound to the solid support. After a suitable incubation period, the solid support is washed and the amount of labeled peptide is quantified. A reduction in the amount of label bound to the solid support is indicative of the presence of antibodies in the original sample. By the same token, the peptide may also be bound to the solid support. Labeled antibody may then be allowed to compete with antibody present in the sample under conditions in which the amount of peptide is limiting. As in the previous example, a reduction in the measured signal is indicative of the presence of antibodies in the sample tested.

Another preferred method of antibody detection is the homogeneous immunoassay. There are many possible variations in the design of such assays. By way of example, numerous possible configurations for homogeneous enzyme immunoassays and methods by which they may be performed are given in Tijssen, P., Practice and Theory of Enzyme Immunoassays, Elsevier Press, Amersham, Oxford, N.Y., 1985. Detection systems which may be employed include those based on enzyme channeling, bioluminescence, allosteric activation and allosteric inhibition. Methods employing liposome-entrapped enzymes or coenzymes may also be used (see Pinnaduwage, P. and Huang, L., Clin. Chem. (1988) 34/2: 268-272, and Ullman, E. F. et al., Clin. Chem. (1987) 33/9: 1579-1584 for examples).

The synthesis of the peptides can be achieved in solution or on a solid support. Synthesis protocols generally employ the use t-butyloxycarbonyl- or 9-fluorenylmethoxy-carbonyl-protected activated arido acids. The is procedures for carrying out the syntheses, the types of side-chain protection, and the cleavage methods are amply described in, for example, Stewart and Young, Solid Phase Peptide Synthesis, 2nd Edition, Pierce Chemical Company, 1984; and Atherton and Sheppard, Solid Phase Peptide Synthesis, IRL Press, 1989.

Experimental

I. Peptide Synthesis

All of the peptides described were synthesized on Pepsyn K polyamide-Kieselguhr resin (Milligen, Novato, Calif.) which had been functionalized with ethylenediamine and onto which the acid-labile linker 4-(alpha-Fmoc-amino-2′,4′-dimethoxybenzyl) phenoxyacetic acid had been coupled (Rink, Tetrahedron Lett. (1987) 28:3787). t-Butyl-based side-chain protection and Fmoc alpha-amino-protection was used. The guanidino-group of arginine was protected by the 2,2,5,7,8-pentamethylchroman-6-sulfonyl moiety. The imidazole group of histidine was protected by either t-Boc or trityl and the sulfhydryl group of cysteine was protected by a trityl group. Couplings were carried out using performed O-pentafluorophenyl esters except in the case of arginine where diisopropylcarbodiimide-mediated hydroxybenzotriazole ester formation was employed. Except for peptide I, all peptides were N-acetylated using acetic anhydride. All syntheses were carried out on a Milligen 9050 PepSynthesizer (Novato, Calif.) using continuous flow procedures. Following cleavage with trifluoroacetic acid in the presence of scavengers and extraction with diethylether, all peptides were analyzed by C₁₈-reverse phase chromatography.

II. Detection of Antibodies to Hepatitis C Virus

A. Use of Peptides Bound to a Nylon Membrane

Peptides were dissolved in a suitable buffer to make a concentrated stock solution which was then further diluted in phosphate-buffered saline (PBS) or sodium carbonate buffer, pH 9.6 to make working solutions. The peptides were applied as lines on a nylon membrane (Pall, Portsmouth, United Kingdom), after which the membrane was treated with casein to block unoccupied binding sites. The membrane was subsequently cut into strips perpendicular to the direction of the peptide lines. Each strip was then incubated with a serum sample diluted 1 to 100, obtained from an HCV-infected individual. Antibody binding was detected by incubating the strips with goat anti-human immunoglobulin antibodies conjugated to the enzyme alkaline phosphatase. After removing unbound conjugate by washing, a substrate solution containing 5-bromo4-chloro-3-indolylphosphate and nitro blue tetrazolium was added.

Positive reactions are visible as colored lines corresponding to the positions of the peptides which are specifically recognized. The reaction patterns of thirty-six different sera are tabulated in Table 1. The results shown in Table 1 are further summarized in Table 2.

B. Use of Peptides in an Enzyme-linked Immunosorbent Assay (ELISA)

Peptide stock solutions were diluted in sodium carbonate buffer, pH 9.6 and used to coat microtiter plates at a peptide concentration of as 2 micrograms per milliliter. A mixture consisting of peptides II, III, V, IX, and XVIII was also used to coat plates. Following coating, the plates were blocked with casein. Fifteen HCV-antibody-positive sera and control sera from seven uninfected blood donors were diluted 1 to 20 and incubated in wells of the peptide-coated plates. Antibody binding was detected by incubating the plates with goat anti-human immunoglobulin antibodies conjugated to the enzyme horseradish peroxidase. Following removal of unbound conjugate by washing, a solution containing H₂O₂ and 3,3′,5,5′-tetramethylbenzidine was added. Reactions were stopped after a suitable interval by addition of sulfuric acid. Positive reactions gave rise to a yellow color which was quantified using a conventional microtiter plate reader. The results of these determinations are tabulated in Table 3. To correct for any aspecific binding which could be attributable to the physical or chemical properties of the peptides themselves, a cut-off value was determined for each peptide individually. This cut-off absorbance value was calculated as the average optical density of the negative samples plus 0.200. Samples giving absorbance values higher than the cut-off values are considered positive. The results for the fifteen positive serum samples are further summarized in Table 4.

While it is evident that some of the peptides are recognized by a large percentage of sera from HCV-infected individuals, it is also clear that no single peptide is recognized by all sera. In contrast, the peptide mixture was recognized by all fifteen sera and, for six of the fifteen sera, the optical densities obtained were equal to or higher than those obtained for any of the peptides individually. These results serve to illustrate the advantages of using mixtures of peptides for the detection of anti-HCV antibodies.

C. Binding of Antibodies in Sera from HCV-infected Patients to Various Individual Peptides and Peptide Mixtures in an ELISA

Five peptides were used individually and in seven different combinations to coat microtiter plates. The plates were subsequently incubated with dilutions of fifteen HCV antibody-positive sera in order to evaluate the relative merits of using mixtures as compared to individual peptides for antibody detection. The mixtures used and the results obtained are shown in FIG. 2.

In general, the mixtures functioned better than individual peptides. This was particularly evident for mixture 12 (peptides I, III, V, IX, and XVIII) which was recognized by all twelve of the sera tested. These results underscore the advantages of using mixtures of peptides in diagnostic tests for the detection of antibodies to HCV.

D. Use of a Mixture of Peptides in an ELISA Assay for the Detection of Anti-HCV Antibodies

A mixture of peptides II, III, V, IX, and XVIII was prepared and used to coat microtiter plates according to the same procedure used to test the individual peptides. A total of forty-nine sera were tested from patients with clinically diagnosed but undifferentiated chronic non A non B hepatitis as well as forty-nine sera from healthy blood donors. Detection of antibody binding was accomplished using goat anti-human immunoglobulin antibodies conjugated to horseradish peroxidase. The resulting optical density values are given in Table 5. These results indicate that the mixture of peptides is not recognized by antibodies in sera from healthy donors (0/49 reactives) but is recognized by a large proportion (41/49, or 84%) of the sera from patients with chronic NANBH. These results demonstrate that the peptides described can be used effectively as mixtures for the diagnosis of HCV infection.

E. Detection of Anti-HCV Antibodies in Sera from Patients with Acute NANB Infection Using Individual Peptides Bound to Nylon Membranes and a Mixture of Peptides in an ELISA Assay, and Comparison with a Commercially Available Kit

Peptides were applied to nylon membranes or mixed and used to coat microtiter plates as previously described. The peptide mixture consisted of peptides II, III, V, IX, and XVIII. Sera obtained from twenty-nine patients with acute non-A, non-B hepatitis were then tested for the presence of antibodies to hepatitis C virus. These same sera were also evaluated using a commercially available kit (Ortho, Emeryville, Calif., USA).

The results of this comparative study are given in Table 6. In order to be able to compare the peptide-based ELISA with the commercially available kit, the results for both tests are also expressed as signal to noise ratios (S/N) which were calculated by dividing the measured optical density obtained for each sample by the cut-off value. A signal-to-noise ratio greater or equal to 1.0 is taken to represent a positive reaction. For the commercially available kit, the cut-off value was calculated according to the manufacturer's instructions. The cut-off value for the peptide-based ELISA was calculated as the average optical density of five negative samples plus 0.200.

The scale used to evaluate antibody recognition of nylon-bound peptides was the same as that given in Table 1. Of the twenty-nine samples tested, twenty-five (86%) were positive in the peptide-based ELISA and recognized one or more nylon-bound peptides. In contrast, only fourteen of the twenty-nine sera scored positive in the commercially available ELISA These results serve to illustrate the advantages of using peptide mixtures for the detection of anti-HIV antibodies as well as the need to include in the mixtures peptides which contain amino acid sequences derived from different regions of the HCV polyprotein.

TABLE 1 Recognition of peptides bound to nylon membranes by sera from persons infected by HCV. PEPTIDE Serum nr. I II III IV V VI VII VIII IX X XI XII XIII XIV XV XVI XVII XVIII XIX 1 3 1 1 0.5 2 2 1 1 2 0.5 1 2 2 1 3 1 0.5 2 1 0.5 2 0.5 1 0.5 4 1 6 2 1 0.5 2 7 0.5 1 2 1 0.5 3 2 2 1 1 2 0.5 1 1 8 0.5 1 3 1 1 1 1 2 1 1 1 1 0.5 10 1 0.5 3 1 1 0.5 2 2 2 2 13 0.5 0.5 2 0.5 1 1 0.5 0.5 15 0.5 2 1 0.5 1 0.5 16 2 1 0.5 0.5 1 0.5 2 0.5 1 2 2 1 2 18 1 1 3 0.5 2 0.5 1 0.5 23 0.5 1 1 0.5 1 0.5 0.5 0.5 24 1 0.5 2 1 0.5 0.5 0.5 2 1 25 1 0.5 2 0.5 0.5 2 1 1 2 26 1 0.5 27 0.5 0.5 1 3 2 1 2 1 0.5 29 0.5 3 2 1 1 0.5 2 1 1 1 2 2 1 1 1 30 0.5 0.5 1 1 0.5 31 1 0.5 0.5 0.5 0.5 32 1 2 1 0.5 1 1 33 0.5 1 0.5 0.5 34 1 1 1 3 1 1 1 0.5 35 1 1 2 1 1 1 0.5 36 1 2 1 1 37 1 1 44 1 2 1 0.5 2 0.5 46 0.5 2 0.5 0.5 0.5 2 47 0.5 0.5 0.5 1 1 1 48 1 2 2 0.5 2 0.5 1 1 1 0.5 49 1 1 0.5 0.5 0.5 0.5 0.5 0.5 1 1 50 1 2 1 2 0.5 1 1 1 1 1 0.5 0.5 51 2 0.5 0.5 0.5 1 1 0.5 52 2 0.5 0.5 0.5 54 2 0.5 0.5 1 0.5 1 1 1 1 1 1 56 ND ND ND ND ND ND ND 2 0.5 1 2 1 Blank: no reaction; 0.5: weakly positive; 1: clearly positive; 2: strong reaction; 3: intense reaction; ND: not determined

TABLE 2 Summary of antibody binding to nylon-bound HCV peptides by sera from infected patients. Peptide No. reactive sera % reactive sera I 13/35 37 II 22/35 63 III 27/35 77 IV 24/35 69 V 14/35 40 VI 11/35 31 VII 11/35 31 VIII 19/36 53 IX  9/36 25 X 17/36 47 XI 15/36 42 XII  1/36 3 XIII 13/36 36 XIV  7/36 19 XV  9/36 25 XVI 20/36 56 XVII 14/36 39 XVIII 14/36 39 XIX  8/36 22

TABLE 3 Comparison of Individual Peptides in an ELISA Assay for the Detection of Antibodies to HCV. sample peptide ident I II III IV V VI VII VIII IX X XI XII XIII XIV XV XVI XVII XVIII XIX  1 0.786 1.119 1.284 0.265 0.042 0.04 0.05 0.571 0.659 0.048 0.04 0.043 0.068 0.044 0.041 1.063 0.956 1.383 1.346  2 0.044 0.039 0.11 0.041 0.037 0.038 0.039 0.479 0.78 0.169 0.563 0.039 0.042 0.515 0.039 0.64 0.319 0.154 0.49  3 0.815 0.944 0.825 0.399 0.654 0.487 0.32 0.705 0.965 0.468 0.668 0.041 0.093 0.341 0.043 0.292 0.038 0.046 0.038  7 1.122 1.23 0.588 0.682 0.659 0.182 0.107 0.907 1.42 0.663 0.646 0.041 0.235 0.068 0.575 0.042 0.041 0.872 1.271  8 1.155 1.159 1.2 0.508 1.272 0.433 0.623 0.61 0.863 0.752 1.175 0.046 0.42 0.102 0.068 0.552 0.671 0.417 0.058 10 1.089 1.236 1.083 0.044 0.508 0.042 0.073 1.49 1.529 0.689 0.834 0.041 0.044 0.314 0.793 0.886 0.037 1.335 1.356 11 0.048 0.051 0.476 0.052 0.119 0.039 0.1 0.634 0.711 0.199 0.967 0.125 0.454 0.088 0.111 0.274 0.093 0.838 0.065 15 0.224 0.602 0.813 0.093 0.068 0.077 0.147 0.807 1.225 0.315 0.688 0.046 0.154 0.202 0.065 0.372 0.097 0.155 0.077 23 0.62 0.8 0.924 0.568 0.759 0.442 0.683 0.089 0.121 0.422 0.896 0.041 0.049 0.101 0.068 0.311 0.038 0.052 0.05 24 1.042 1.132 1.026 0.518 0.916 0.302 0.253 1.013 1.364 0.236 0.397 0.054 0.123 0.076 0.051 0.418 0.053 0.1 0.085 49 0.624 0.73 0.884 0.171 0.372 0.055 0.04 0.084 0.064 0.209 0.731 0.044 0.113 0.039 0.044 0.299 0.038 0.192 0.041 13 0.76 0.857 0.815 0.087 0.422 0.098 0.045 0.473 0.489 0.529 0.735 0.043 0.044 0.186 0.043 0.086 0.037 0.066 0.04 31 0.84 1.114 0.445 0.672 0.046 0.041 0.042 0.184 0.15 0.255 0.69 0.041 0.04 0.061 0.136 0.292 0.038 0.224 0.501 47 1.303 1.53 1.236 0.751 0.83 0.629 0.073 0.545 0.739 0.044 0.041 0.041 0.041 0.498 0.04 0.268 0.042 1.288 1.206 56 1.169 1.301 1.364 1.269 1.374 0.85 1.066 1.45 1.523 0.079 1.069 0.058 0.568 0.038 0.039 0.218 0.036 0.087 0.039 bd A28 0.054 0.043 0.139 0.045 0.135 0.042 0.041 0.086 0.115 0.044 0.042 0.044 0.052 0.043 0.043 0.307 0.042 0.045 0.061 bd A169 0.041 0.042 0.134 0.044 0.038 0.04 0.041 0.061 0.07 0.043 0.042 0.041 0.04 0.041 0.041 0.255 0.038 0.056 0.042 bd A170 0.04 0.044 0.117 0.04 0.036 0.04 0.04 0.081 0.05 0.04 0.039 0.04 0.038 0.038 0.144 0.292 0.036 0.058 0.039 bd A171 0.041 0.046 0.148 0.043 0.037 0.045 0.045 0.077 0.065 0.043 0.041 0.043 0.039 0.04 0.045 0.286 0.037 0.05 0.04 bd A166 0.047 0.046 0.124 0.044 0.038 0.042 0.041 0.056 0.066 0.041 0.041 0.042 0.04 0.041 0.041 0.207 0.039 0.046 0.041 bd A165 0.041 0.046 0.123 0.043 0.035 0.051 0.042 0.051 0.091 0.041 0.04 0.042 0.039 0.043 0.039 0.253 0.034 0.06 0.098 AVG 0.044 0.045 0.131 0.043 0.053 0.043 0.042 0.069 0.076 0.012 0.041 0.042 0.041 0.041 0.059 0.267 0.038 0.053 0.054 STD 0.005 0.002 0.011 0.002 0.037 0.004 0.002 0.013 0.021 0.001 0.001 0.001 0.005 0.002 0.038 0.033 0.002 0.006 0.021 cut off 0.109 0.101 0.214 0.099 0.214 0.105 0.098 0.158 0.189 0.095 0.094 0.095 0.106 0.097 0.223 0.416 0.084 0.121 0.167

TABLE 4 Summary of antibody-binding to individual peptides in an ELISA assay. Peptide No. reactive sera % reactive sera I 13 87 II 13 87 III 14 93 IV 10 67 V 10 67 VI 7 47 VII 8 53 VIII 13 87 IX 12 80 X 13 87 XI 13 87 XII 1 7 XIII 7 47 XIV 8 53 XV 2 13 XVI 5 33 XVII 4 27 XVIII 10 67 XIX 6 40

TABLE 5 Use of a peptide mixture for the detection of antibodies to HCV in sera from chronic NANBH patients and comparison to sera from healthy blood donors. Chronic NANB Sera Control Sera Serum nr. Optical Density Serum nr. Optical Density 101 0.041 1 0.049 102 1.387 2 0.047 103 1.578 3 0.049 104 1.804 4 0.046 105 1.393 5 0.049 107 1.604 6 0.045 108 1.148 7 0.043 109 1.714 8 0.053 110 1.692 9 0.049 112 0.919 10 0.047 113 1.454 11 0.060 114 0.936 12 0.044 115 0.041 13 0.049 116 1.636 14 0.051 118 1.242 15 0.056 119 1.568 16 0.050 120 1.290 17 0.049 121 1.541 18 0.055 122 1.422 19 0.054 123 1.493 20 0.058 124 1.666 21 0.050 125 1.644 22 0.044 126 1.409 23 0.043 127 1.625 24 0.045 128 1.061 25 0.046 129 1.553 26 0.049 130 1.709 27 0.050 131 0.041 28 0.047 132 0.044 29 0.050 133 1.648 30 0.053 134 −0.043 31 0.051 135 1.268 32 0.053 136 1.480 33 0.055 138 0.628 34 0.064 139 0.042 35 0.063 140 0.040 36 0.057 141 0.039 38 0.048 142 1.659 39 0.045 143 1.457 40 0.046 144 0.722 41 0.046 145 1.256 42 0.051 146 0.373 43 0.057 147 1.732 44 0.050 148 1.089 45 0.050 149 1.606 46 0.045 150 1.725 47 0.041 151 1.449 48 0.064 154 1.639 49 0.040 155 1.775 50 0.036

TABLE 6 Comparison of anti-HCV antibody detection by nylon-bound peptides, a peptide-based ELISA, and a commercially available kit. Optical Optical density density Nylon-bound peptides Peptide Commercial Serum. nr. I III IV V VI VIII XI XIV XV XVI XVIII ELISA S/N ELISA S/N 191 0 0 0 0 0 0 0 0 0 0 0 0.045 0.18 0.295 0.47 192 0 0 0 0 0 0 0 0 0 0 0 0.042 0.17 0.289 0.46 193 0 0 0 0 0 0 0 0 0 0 0 0.039 0.16 0.197 0.32 194 0 0 0 0 0 0 0 G 0 0 0 0.044 0.18 0.183 0.29 195 1 2 2 3 0 0 0.5 0.5 1 3 1 1.692 6.77 3.000* 4.82* 196 1 2 1 2 0.5 0.5 0.5 0.5 0.5 2 0 1.569 6.28 0.386 0.62 197 1 2 1 2 0 0.5 0.5 0.5 1 2 0 1.523 6.09 0.447 0.72 198 1 2 2 2 0 0 0 0 1 2 0 1.578 6.31 0.354 0.57 211 0.5 1 0.5 0.5 0 2 2 0 2 0 1 1.606 6.42 3.000* 4.82* 213 0 0 0 1 0 0 0 0 0 0 0 0.369 1.48 0.127 0.20 214 0 0 0 1 0 0 0 0 0 0 0 0.444 1.78 0.101 0.16 215 0 0 0 1 0 0 0 0 0 0 0 0.637 2.55 0.101 0.16 216 0 0 0 0.5 0 0 0 0 0 0 0 0.812 3.25 0.092 0.15 217 0 0 0 1 0 0 0 0 0 0 0 1.320 5.28 0.875 1.40 219 0.5 1 1 2 1 0.5 1 0 0.5 0.5 1 1.547 6.19 3.000* 4.82* 220 0.5 1 1 2 1 0.5 1 0 0.5 0.5 1 1.536 6.14 3.000* 4.82* 221 0 0 0.5 0 0 0 0 0 0 0 0 1.428 5.71 0.327 0.52 222 1 1 1 1 0 0 2 0.5 0.5 0 0 1.362 5.45 3.000* 4.82* 223 1 1 1 1 0 0 3 0.5 0.5 0 0 1.316 5.26 3.000* 4.82* 224 1 1 2 1 0 0.5 3 0.5 0.5 0 0 1.304 5.22 3.000* 4.82* 225 0 0 0 0 0 0.5 0.5 0.5 0 0 2 1.178 4.71 2.398 3.85 226 0.5 0 0 0 0 2 3 2 0.5 0.5 3 1.256 5.14 3.000* 4.82* 227 0 0 0 0 0 2 2 0.5 0.5 0.5 2 1.335 5.34 3.000* 4.82* 228 0.5 0 0.5 0.5 0 2 2 2 0 0 2 1.400 5.60 3.000* 4.82* 234 0.5 0.5 0 0.5 0 0 3 1 3 1 3 1.481 5.92 3.000* 4.82* 235 0 0 0 0.5 0 0 0 0 0 0 0 0.351 1.40 0.257 0.41 236 0 0 0 0.5 0 0 0 0 0 0 0 0.475 1.90 0.245 0.39 237 0 0 0 1 0 0 0 0 0 0 0 1.134 4.54 0.351 0.56 238 0 0 0 1 0 1 1 0 0 0 0 1.096 4.38 1.074 1.72 Cut-off: 0.250 Cut-off: 0.623 0: no reaction; 0.5: weakly positive; 1: clearly positive; 2: strong reaction; 3: intense reaction; *O.D. exceeded 3,000 and was out of range. The values given are therefore minimum values.

23 20 amino acids amino acid single linear peptide 1 Met Ser Thr Ile Pro Lys Pro Gln Arg Lys Thr Lys Arg Asn Thr As 1 5 10 15 Arg Arg Pro Gln 20 20 amino acids amino acid single linear peptide 2 Pro Gln Arg Lys Thr Lys Arg Asn Thr Asn Arg Arg Pro Gln Asp Va 1 5 10 15 Lys Phe Pro Gly 20 11 amino acids amino acid single linear peptide 3 Gln Arg Lys Thr Lys Arg Asn Thr Asn Arg Arg 1 5 10 20 amino acids amino acid single linear peptide 4 Arg Asn Thr Asn Arg Arg Pro Gln Asp Val Lys Phe Pro Gly Gly Gl 1 5 10 15 Gln Ile Val Gly 20 20 amino acids amino acid single linear peptide 5 Leu Pro Arg Arg Gly Pro Arg Leu Gly Val Arg Ala Thr Arg Lys Th 1 5 10 15 Ser Glu Arg Ser 20 20 amino acids amino acid single linear peptide 6 Thr Arg Lys Thr Ser Glu Arg Ser Gln Pro Arg Gly Arg Arg Gln Pr 1 5 10 15 Ile Pro Lys Val 20 20 amino acids amino acid single linear peptide 7 Arg Arg Gln Pro Ile Pro Lys Val Arg Arg Pro Glu Gly Arg Thr Tr 1 5 10 15 Ala Gln Pro Gly 20 20 amino acids amino acid single linear peptide 8 Gly Arg Thr Trp Ala Gln Pro Gly Tyr Pro Trp Pro Leu Tyr Gly As 1 5 10 15 Glu Gly Cys Gly 20 20 amino acids amino acid single linear peptide 9 Leu Ser Gly Lys Pro Ala Ile Ile Pro Asp Arg Glu Val Leu Tyr Ar 1 5 10 15 Glu Phe Asp Glu 20 20 amino acids amino acid single linear peptide 10 Ile Ile Pro Asp Arg Glu Val Leu Tyr Arg Glu Phe Asp Glu Met Gl 1 5 10 15 Glu Cys Ser Gln 20 20 amino acids amino acid single linear peptide 11 Asp Glu Met Glu Glu Cys Ser Gln His Leu Pro Tyr Ile Glu Gln Gl 1 5 10 15 Met Met Leu Ala 20 20 amino acids amino acid single linear peptide 12 Ser Gln His Leu Pro Tyr Ile Glu Gln Gly Met Met Leu Ala Glu Gl 1 5 10 15 Phe Lys Gln Lys 20 20 amino acids amino acid single linear peptide 13 Ile Glu Gln Gly Met Met Leu Ala Glu Gln Phe Lys Gln Lys Ala Le 1 5 10 15 Gly Leu Leu Gln 20 20 amino acids amino acid single linear peptide 14 Leu Ala Glu Gln Phe Lys Gln Lys Ala Leu Gly Leu Leu Gln Thr Al 1 5 10 15 Ser Arg Gln Ala 20 20 amino acids amino acid single linear peptide 15 Gln Lys Ala Leu Gly Leu Leu Gln Thr Ala Ser Arg Gln Ala Glu Va 1 5 10 15 Ile Ala Pro Ala 20 20 amino acids amino acid single linear peptide 16 Glu Asp Glu Arg Glu Ile Ser Val Pro Ala Glu Ile Leu Arg Lys Se 1 5 10 15 Arg Arg Phe Ala 20 20 amino acids amino acid single linear peptide 17 Leu Arg Lys Ser Arg Arg Phe Ala Gln Ala Leu Pro Val Trp Ala Ar 1 5 10 15 Pro Asp Tyr Asn 20 20 amino acids amino acid single linear peptide 18 Val Trp Ala Arg Pro Asp Tyr Asn Pro Pro Leu Val Glu Thr Trp Ly 1 5 10 15 Lys Pro Asp Tyr 20 20 amino acids amino acid single linear peptide 19 Glu Thr Trp Lys Lys Pro Asp Tyr Glu Pro Pro Val Val His Gly Cy 1 5 10 15 Pro Leu Pro Pro 20 20 amino acids amino acid single linear peptide 20 Val His Gly Cys Pro Leu Pro Pro Pro Lys Ser Pro Pro Val Pro Pr 1 5 10 15 Pro Arg Lys Lys 20 16 amino acids amino acid single linear peptide 21 Glu Arg Glu Ile Ser Val Pro Ala Glu Ile Leu Arg Lys Ser Arg Ar 1 5 10 15 11 amino acids amino acid single linear peptide 22 Arg Phe Ala Gln Ala Leu Pro Val Trp Ala Arg 1 5 10 2894 amino acids amino acid single linear peptide NO NO 23 Met Ser Thr Ile Pro Lys Pro Gln Arg Lys Thr Lys Arg Asn Thr As 1 5 10 15 Arg Arg Pro Gln Asp Val Lys Phe Pro Gly Gly Gly Gln Ile Val Gl 20 25 30 Gly Val Tyr Leu Leu Pro Arg Arg Gly Pro Arg Leu Gly Val Arg Al 35 40 45 Thr Arg Lys Thr Ser Glu Arg Ser Gln Pro Arg Gly Arg Arg Gln Pr 50 55 60 Ile Pro Lys Val Arg Arg Pro Glu Gly Arg Thr Trp Ala Gln Pro Gl 65 70 75 80 Tyr Pro Trp Pro Leu Tyr Gly Asn Glu Gly Cys Gly Trp Ala Gly Tr 85 90 95 Leu Leu Ser Pro Arg Gly Ser Arg Pro Ser Trp Gly Pro Thr Asp Pr 100 105 110 Arg Arg Arg Ser Arg Asn Leu Gly Lys Val Ile Asp Thr Leu Thr Cy 115 120 125 Gly Phe Ala Asp Leu Met Gly Tyr Ile Pro Leu Val Gly Ala Pro Le 130 135 140 Gly Gly Ala Ala Arg Ala Leu Ala His Gly Val Arg Val Leu Glu As 145 150 155 160 Gly Val Asn Tyr Ala Thr Gly Asn Leu Pro Gly Cys Ser Phe Ser Il 165 170 175 Phe Leu Leu Ala Leu Leu Ser Cys Leu Thr Val Pro Ala Ser Ala Ty 180 185 190 Gln Val Arg Asn Ser Thr Gly Leu Tyr His Val Thr Asn Asp Cys Pr 195 200 205 Asn Ser Ser Ile Val Tyr Glu Ala His Asp Ala Ile Leu His Thr Pr 210 215 220 Gly Cys Val Pro Cys Val Arg Glu Gly Asn Val Ser Arg Cys Trp Va 225 230 235 240 Ala Met Thr Pro Thr Val Ala Thr Arg Asp Gly Lys Leu Pro Ala Th 245 250 255 Gln Leu Arg Arg His Ile Asp Leu Leu Val Gly Ser Ala Thr Leu Cy 260 265 270 Ser Ala Leu Tyr Val Gly Asp Leu Cys Gly Ser Val Phe Leu Ile Gl 275 280 285 Gln Leu Phe Thr Phe Ser Pro Arg Arg His Trp Thr Thr Gln Gly Cy 290 295 300 Asn Cys Ser Ile Tyr Pro Gly His Ile Thr Gly His Arg Met Ala Tr 305 310 315 320 Asp Met Met Met Asn Trp Ser Pro Thr Ala Ala Leu Val Met Ala Gl 325 330 335 Leu Leu Arg Ile Pro Gln Ala Ile Leu Asp Met Ile Ala Gly Ala Hi 340 345 350 Trp Gly Val Leu Ala Gly Ile Ala Tyr Phe Ser Met Val Gly Asn Tr 355 360 365 Ala Lys Val Leu Val Val Leu Leu Leu Phe Ala Gly Val Asp Ala Gl 370 375 380 Thr Ile Val Ser Gly Gly Gln Ala Ala Arg Ala Met Ser Gly Leu Va 385 390 395 400 Ser Leu Phe Thr Pro Gly Ala Lys Gln Asn Ile Gln Leu Ile Asn Th 405 410 415 Asn Gly Ser Trp His Ile Asn Ser Thr Ala Leu Asn Cys Asn Glu Se 420 425 430 Leu Asn Thr Gly Trp Leu Ala Gly Leu Ile Tyr Gln His Lys Phe As 435 440 445 Ser Ser Gly Cys Pro Glu Arg Leu Ala Ser Cys Arg Pro Leu Thr As 450 455 460 Phe Asp Gln Gly Trp Gly Pro Ile Ser Tyr Ala Asn Gly Ser Gly Pr 465 470 475 480 Asp Gln Arg Pro Tyr Cys Trp His Tyr Pro Pro Lys Pro Cys Gly Il 485 490 495 Val Pro Ala Lys Ser Val Cys Gly Pro Val Tyr Cys Phe Thr Pro Se 500 505 510 Pro Val Val Val Gly Thr Thr Asp Arg Ser Gly Ala Pro Thr Tyr Se 515 520 525 Trp Gly Glu Asn Asp Thr Asp Val Phe Val Leu Asn Asn Thr Arg Pr 530 535 540 Pro Leu Gly Asn Trp Phe Gly Cys Thr Trp Met Asn Ser Thr Gly Ph 545 550 555 560 Thr Lys Val Cys Gly Ala Pro Pro Cys Val Ile Gly Gly Ala Gly As 565 570 575 Asn Thr Leu His Cys Pro Thr Asp Cys Phe Arg Lys His Pro Asp Al 580 585 590 Thr Tyr Ser Arg Cys Gly Ser Gly Pro Trp Ile Thr Pro Arg Cys Le 595 600 605 Val Asp Tyr Pro Tyr Arg Leu Trp His Tyr Pro Cys Thr Ile Asn Ty 610 615 620 Thr Ile Phe Lys Ile Arg Met Tyr Val Gly Gly Val Glu His Arg Le 625 630 635 640 Glu Ala Ala Cys Asn Trp Thr Arg Gly Glu Arg Cys Asp Leu Glu As 645 650 655 Arg Asp Arg Ser Glu Leu Ser Pro Leu Leu Leu Thr Thr Thr Gln Tr 660 665 670 Gln Val Leu Pro Cys Ser Phe Thr Thr Leu Pro Ala Leu Ser Thr Gl 675 680 685 Leu Ile His Leu His Gln Asn Ile Val Asp Val Gln Tyr Leu Tyr Gl 690 695 700 Val Gly Ser Ser Ile Ala Ser Trp Ala Ile Lys Trp Glu Tyr Val Va 705 710 715 720 Leu Leu Phe Leu Leu Leu Ala Asp Ala Arg Val Cys Ser Cys Leu Tr 725 730 735 Met Met Leu Leu Ile Ser Gln Ala Glu Ala Ala Leu Glu Asn Leu Va 740 745 750 Ile Leu Asn Ala Ala Ser Leu Ala Gly Thr His Gly Leu Val Ser Ph 755 760 765 Leu Val Phe Phe Cys Phe Ala Trp Tyr Leu Lys Gly Lys Trp Val Pr 770 775 780 Gly Ala Val Tyr Thr Phe Tyr Gly Met Trp Pro Leu Leu Leu Leu Le 785 790 795 800 Leu Ala Leu Pro Gln Arg Ala Tyr Ala Leu Asp Thr Glu Val Ala Al 805 810 815 Ser Cys Gly Gly Val Val Leu Val Gly Leu Met Ala Leu Thr Leu Se 820 825 830 Pro Tyr Tyr Lys Arg Tyr Ile Ser Trp Cys Leu Trp Trp Leu Gln Ty 835 840 845 Phe Leu Thr Arg Val Glu Ala Gln Leu His Val Trp Ile Pro Pro Le 850 855 860 Asn Val Arg Gly Gly Arg Asp Ala Val Ile Leu Leu Met Cys Ala Va 865 870 875 880 His Pro Thr Leu Val Phe Asp Ile Thr Lys Leu Leu Leu Ala Val Ph 885 890 895 Gly Pro Leu Trp Ile Leu Asp Ala Ser Leu Leu Lys Val Pro Tyr Ph 900 905 910 Val Arg Val Gln Gly Leu Leu Arg Phe Cys Ala Leu Ala Arg Lys Me 915 920 925 Ile Gly Gly His Tyr Val Gln Met Val Ile Ile Lys Leu Gly Ala Le 930 935 940 Thr Gly Thr Tyr Val Tyr Asn His Leu Thr Pro Leu Arg Asp Trp Al 945 950 955 960 His Asn Gly Leu Arg Asp Leu Ala Val Ala Val Glu Pro Val Val Ph 965 970 975 Ser Gln Met Glu Thr Lys Leu Ile Thr Trp Gly Ala Asp Thr Ala Al 980 985 990 Cys Gly Asp Ile Ile Asn Gly Leu Pro Val Ser Ala Arg Arg Gly Ar 995 1000 1005 Glu Ile Leu Leu Gly Pro Ala Asp Gly Met Val Ser Lys Gly Trp Ar 1010 1015 1020 Leu Leu Ala Pro Ile Thr Ala Tyr Ala Gln Gln Thr Arg Gly Leu Le 1025 1030 1035 1040 Gly Cys Ile Ile Thr Ser Leu Thr Gly Arg Asp Lys Asn Gln Val Gl 1045 1050 1055 Gly Glu Val Gln Ile Val Ser Thr Ala Ala Gln Thr Phe Leu Ala Th 1060 1065 1070 Cys Ile Asn Gly Val Cys Trp Thr Val Tyr His Gly Ala Gly Thr Ar 1075 1080 1085 Thr Ile Ala Ser Pro Lys Gly Pro Val Ile Gln Met Tyr Thr Asn Va 1090 1095 1100 Asp Gln Asp Leu Val Gly Trp Pro Ala Pro Gln Gly Ser Arg Ser Le 1105 1110 1115 1120 Thr Pro Cys Thr Cys Gly Ser Ser Asp Leu Tyr Leu Val Thr Arg Hi 1125 1130 1135 Ala Asp Val Ile Pro Val Arg Arg Arg Gly Asp Ser Arg Gly Ser Le 1140 1145 1150 Leu Ser Pro Arg Pro Ile Ser Tyr Leu Lys Gly Ser Ser Gly Gly Pr 1155 1160 1165 Leu Leu Cys Pro Ala Gly His Ala Val Gly Ile Phe Arg Ala Ala Va 1170 1175 1180 Cys Thr Arg Gly Val Ala Lys Ala Val Asp Phe Ile Pro Val Glu As 1185 1190 1195 1200 Leu Glu Thr Thr Met Arg Ser Pro Val Phe Trp Asp Asn Ser Ser Pr 1205 1210 1215 Pro Val Val Pro Gln Ser Phe Gln Val Ala His Leu His Ala Pro Th 1220 1225 1230 Gly Ser Gly Lys Ser Thr Lys Val Pro Ala Ala Tyr Ala Ala Gln Gl 1235 1240 1245 Tyr Lys Val Leu Val Leu Asn Pro Ser Val Ala Ala Thr Leu Gly Ph 1250 1255 1260 Gly Ala Tyr Met Ser Lys Ala His Gly Ile Asp Pro Asn Ile Arg Th 1265 1270 1275 1280 Gly Val Arg Thr Ile Thr Thr Gly Ser Pro Ile Thr Tyr Ser Thr Ty 1285 1290 1295 Gly Lys Phe Leu Ala Asp Gly Gly Cys Ser Gly Gly Ala Tyr Asp Il 1300 1305 1310 Ile Ile Cys Asp Glu Cys His Ser Thr Asp Ala Thr Ser Ile Leu Gl 1315 1320 1325 Ile Gly Thr Val Leu Asp Gln Ala Glu Thr Ala Gly Ala Arg Leu Va 1330 1335 1340 Val Leu Ala Thr Ala Thr Pro Pro Gly Ser Val Thr Val Pro His Pr 1345 1350 1355 1360 Asn Ile Glu Glu Val Ala Leu Ser Thr Thr Gly Glu Ile Pro Phe Ty 1365 1370 1375 Gly Lys Ala Ile Pro Leu Glu Val Ile Lys Gly Gly Arg His Leu Il 1380 1385 1390 Phe Cys His Ser Lys Lys Lys Cys Asp Glu Leu Ala Ala Lys Leu Va 1395 1400 1405 Ala Leu Gly Ile Asn Ala Val Ala Tyr Tyr Arg Gly Leu Asp Val Se 1410 1415 1420 Val Ile Pro Thr Ser Gly Asp Val Val Val Val Ala Thr Asp Ala Le 1425 1430 1435 1440 Met Thr Gly Tyr Thr Gly Asp Phe Asp Ser Val Ile Asp Cys Asn Th 1445 1450 1455 Cys Val Thr Gln Thr Val Asp Phe Ser Leu Asp Pro Thr Phe Thr Il 1460 1465 1470 Glu Thr Ile Thr Leu Pro Gln Asp Ala Val Ser Arg Thr Gln Arg Ar 1475 1480 1485 Gly Arg Thr Gly Arg Gly Lys Pro Gly Ile Tyr Arg Phe Val Ala Pr 1490 1495 1500 Gly Glu Arg Pro Ser Gly Met Phe Asp Ser Ser Val Leu Cys Glu Cy 1505 1510 1515 1520 Tyr Asp Ala Gly Cys Ala Trp Tyr Glu Leu Thr Pro Ala Glu Thr Th 1525 1530 1535 Val Arg Leu Arg Ala Tyr Met Asn Thr Pro Gly Leu Pro Val Cys Gl 1540 1545 1550 Asp His Leu Glu Phe Trp Glu Gly Val Phe Thr Gly Leu Thr His Il 1555 1560 1565 Asp Ala His Phe Leu Ser Gln Thr Lys Gly Ser Gly Glu Asn Leu Pr 1570 1575 1580 Tyr Leu Val Ala Tyr Gln Ala Thr Val Cys Ala Arg Ala Gln Ala Pr 1585 1590 1595 1600 Pro Pro Ser Trp Asp Gln Met Trp Lys Cys Leu Ile Arg Leu Lys Pr 1605 1610 1615 Thr Leu His Gly Pro Thr Pro Leu Leu Tyr Arg Leu Gly Ala Val Gl 1620 1625 1630 Asn Glu Ile Thr Leu Thr His Pro Val Thr Lys Tyr Ile Met Thr Cy 1635 1640 1645 Met Ser Ala Asp Leu Glu Val Val Thr Ser Thr Trp Val Leu Val Gl 1650 1655 1660 Gly Val Leu Ala Ala Leu Ala Ala Tyr Cys Leu Ser Thr Gly Cys Va 1665 1670 1675 1680 Val Ile Val Gly Arg Val Val Leu Ser Gly Lys Pro Ala Ile Ile Pr 1685 1690 1695 Asp Arg Glu Val Leu Tyr Arg Glu Phe Asp Glu Met Glu Glu Cys Se 1700 1705 1710 Gln His Leu Pro Tyr Ile Glu Gln Gly Met Met Leu Ala Glu Gln Ph 1715 1720 1725 Lys Gln Lys Ala Leu Gly Leu Leu Gln Thr Ala Ser Arg Gln Ala Gl 1730 1735 1740 Val Ile Ala Pro Ala Val Gln Thr Asn Trp Gln Lys Leu Glu Thr Ph 1745 1750 1755 1760 Trp Ala Lys His Met Trp Asn Phe Ile Ser Gly Ile Gln Tyr Leu Al 1765 1770 1775 Gly Leu Ser Thr Leu Pro Gly Asn Pro Ala Ile Ala Ser Leu Met Al 1780 1785 1790 Phe Thr Ala Ala Val Thr Ser Pro Leu Thr Thr Ser Gln Thr Leu Le 1795 1800 1805 Phe Asn Ile Leu Gly Gly Trp Val Ala Ala Gln Leu Ala Ala Pro Gl 1810 1815 1820 Ala Ala Thr Ala Phe Val Gly Ala Gly Leu Ala Gly Ala Ala Ile Gl 1825 1830 1835 1840 Ser Val Gly Leu Gly Lys Val Leu Ile Asp Ile Leu Ala Gly Tyr Gl 1845 1850 1855 Ala Gly Val Ala Gly Ala Leu Val Ala Phe Lys Ile Met Ser Gly Gl 1860 1865 1870 Val Pro Ser Thr Glu Asp Leu Val Asn Leu Leu Pro Ala Ile Leu Se 1875 1880 1885 Pro Gly Ala Leu Val Val Gly Val Val Cys Ala Ala Ile Leu Arg Ar 1890 1895 1900 His Val Gly Pro Gly Glu Gly Ala Val Gln Trp Met Asn Arg Leu Il 1905 1910 1915 1920 Ala Phe Ala Ser Arg Gly Asn His Val Ser Pro Thr His Tyr Val Pr 1925 1930 1935 Glu Ser Asp Ala Ala Ala Arg Val Thr Ala Ile Leu Ser Ser Leu Th 1940 1945 1950 Val Thr Gln Leu Leu Arg Arg Leu His Gln Trp Ile Ser Ser Glu Cy 1955 1960 1965 Thr Thr Pro Cys Ser Gly Ser Trp Leu Arg Asp Ile Trp Asp Trp Il 1970 1975 1980 Cys Glu Val Leu Ser Asp Phe Lys Thr Trp Leu Lys Ala Lys Leu Me 1985 1990 1995 2000 Pro Gln Leu Pro Gly Ile Pro Phe Val Ser Cys Gln Arg Gly Tyr Ly 2005 2010 2015 Gly Val Trp Arg Val Asp Gly Ile Met His Thr Arg Cys His Cys Gl 2020 2025 2030 Ala Glu Ile Thr Gly His Val Lys Asn Gly Thr Met Arg Ile Val Gl 2035 2040 2045 Pro Arg Thr Cys Arg Asn Met Trp Ser Gly Thr Phe Pro Ile Asn Al 2050 2055 2060 Tyr Thr Thr Gly Pro Cys Thr Arg Leu Pro Ala Pro Asn Tyr Thr Ph 2065 2070 2075 2080 Ala Leu Trp Arg Val Ser Ala Glu Glu Tyr Val Glu Ile Arg Gln Va 2085 2090 2095 Gly Asp Phe His Tyr Val Thr Gly Met Thr Thr Asp Asn Leu Lys Cy 2100 2105 2110 Pro Cys Gln Val Pro Ser Pro Glu Phe Phe Thr Glu Leu Asp Gly Va 2115 2120 2125 Arg Leu His Arg Phe Ala Pro Pro Cys Lys Pro Leu Leu Arg Glu Gl 2130 2135 2140 Val Ser Phe Arg Val Gly Leu His Glu Tyr Pro Val Gly Ser Gln Le 2145 2150 2155 2160 Pro Cys Glu Pro Glu Pro Asp Val Ala Val Leu Thr Ser Met Leu Th 2165 2170 2175 Asp Pro Ser His Ile Thr Ala Glu Ala Ala Gly Arg Arg Leu Ala Ar 2180 2185 2190 Gly Ser Pro Pro Ser Val Ala Ser Ser Ser Ala Ser Gln Leu Ser Al 2195 2200 2205 Pro Ser Leu Lys Ala Thr Cys Thr Ala Asn His Asp Ser Pro Asp Al 2210 2215 2220 Glu Leu Ile Glu Ala Asn Leu Leu Trp Arg Gln Glu Met Gly Gly As 2225 2230 2235 2240 Ile Thr Arg Val Glu Ser Glu Asn Lys Val Val Ile Leu Asp Ser Ph 2245 2250 2255 Asp Pro Leu Val Ala Glu Glu Asp Glu Arg Glu Ile Ser Val Pro Al 2260 2265 2270 Glu Ile Leu Arg Lys Ser Arg Arg Phe Ala Gln Ala Leu Pro Val Tr 2275 2280 2285 Ala Arg Pro Asp Tyr Asn Pro Pro Leu Val Glu Thr Trp Lys Lys Pr 2290 2295 2300 Asp Tyr Glu Pro Pro Val Val His Gly Cys Pro Leu Pro Pro Pro Ly 2305 2310 2315 2320 Ser Pro Pro Val Pro Pro Pro Arg Lys Lys Arg Thr Val Val Leu Th 2325 2330 2335 Glu Ser Thr Leu Ser Thr Ala Leu Ala Glu Leu Ala Thr Arg Ser Ph 2340 2345 2350 Gly Ser Ser Ser Thr Ser Gly Ile Thr Gly Asp Asn Thr Thr Thr Se 2355 2360 2365 Ser Glu Pro Ala Pro Ser Gly Cys Pro Pro Asp Ser Asp Ala Glu Se 2370 2375 2380 Tyr Ser Ser Met Pro Pro Leu Glu Gly Glu Pro Gly Asp Pro Asp Le 2385 2390 2395 2400 Ser Asp Gly Ser Trp Ser Thr Val Ser Ser Glu Ala Asn Ala Glu As 2405 2410 2415 Val Val Cys Cys Ser Met Ser Tyr Ser Trp Thr Gly Ala Cys Val Th 2420 2425 2430 Pro Cys Ala Ala Glu Glu Gln Lys Leu Pro Ile Asn Ala Leu Ser As 2435 2440 2445 Ser Leu Leu Arg His His Asn Leu Val Tyr Ser Thr Thr Ser Arg Se 2450 2455 2460 Ala Cys Gln Arg Gln Lys Lys Val Thr Phe Asp Arg Leu Gln Val Le 2465 2470 2475 2480 Asp Ser His Tyr Gln Asp Val Leu Lys Glu Val Lys Ala Ala Ala Se 2485 2490 2495 Lys Val Lys Ala Asn Leu Leu Ser Val Glu Glu Ala Cys Ser Leu Th 2500 2505 2510 Pro Pro His Ser Ala Lys Ser Lys Phe Gly Tyr Gly Ala Lys Asp Va 2515 2520 2525 Arg Cys His Ala Arg Lys Ala Val Thr His Ile Asn Ser Val Trp Ly 2530 2535 2540 Asp Leu Leu Glu Asp Asn Val Thr Pro Ile Asp Thr Thr Ile Met Al 2545 2550 2555 2560 Lys Asn Glu Val Phe Cys Val Gln Pro Glu Lys Gly Gly Arg Lys Pr 2565 2570 2575 Ala Arg Leu Ile Val Phe Pro Asp Leu Gly Val Arg Val Cys Glu Ly 2580 2585 2590 Met Ala Leu Tyr Asp Val Val Thr Lys Leu Pro Leu Ala Val Met Gl 2595 2600 2605 Ser Ser Tyr Gly Phe Gln Tyr Ser Pro Gly Gln Arg Val Glu Phe Le 2610 2615 2620 Val Gln Ala Trp Lys Ser Lys Lys Thr Pro Met Gly Phe Ser Tyr As 2625 2630 2635 2640 Thr Arg Cys Phe Asp Ser Thr Val Thr Glu Ser Asp Ile Arg Thr Gl 2645 2650 2655 Glu Ala Ile Tyr Gln Cys Cys Asp Leu Asp Pro Gln Ala Arg Val Al 2660 2665 2670 Ile Lys Ser Leu Thr Glu Arg Leu Tyr Val Gly Gly Pro Leu Thr As 2675 2680 2685 Ser Arg Gly Glu Asn Cys Gly Tyr Arg Arg Cys Arg Ala Ser Gly Va 2690 2695 2700 Leu Thr Thr Ser Cys Gly Asn Thr Leu Thr Cys Tyr Ile Lys Ala Ar 2705 2710 2715 2720 Ala Ala Cys Arg Ala Ala Gly Leu Gln Asp Cys Thr Met Leu Val Cy 2725 2730 2735 Gly Asp Asp Leu Val Val Ile Cys Glu Ser Ala Gly Val Gln Glu As 2740 2745 2750 Ala Ala Ser Leu Arg Ala Phe Thr Glu Ala Met Thr Arg Tyr Ser Al 2755 2760 2765 Pro Pro Gly Asp Pro Pro Gln Pro Glu Tyr Asp Leu Glu Leu Ile Th 2770 2775 2780 Ser Cys Ser Ser Asn Val Ser Val Ala His Asp Gly Ala Gly Lys Ar 2785 2790 2795 2800 Val Tyr Tyr Leu Thr Arg Asp Pro Thr Thr Pro Leu Ala Arg Ala Al 2805 2810 2815 Trp Glu Thr Ala Arg His Thr Pro Val Asn Ser Trp Leu Gly Asn Il 2820 2825 2830 Ile Met Phe Ala Pro Thr Leu Trp Ala Arg Met Ile Leu Met Thr Hi 2835 2840 2845 Phe Phe Ser Val Leu Ile Ala Arg Asp Gln Leu Glu Gln Ala Leu As 2850 2855 2860 Cys Glu Ile Tyr Gly Ala Cys Tyr Ser Ile Glu Pro Leu Asp Leu Pr 2865 2870 2875 2880 Pro Ile Ile Gln Arg Leu Gly Cys Pro Glu Arg Leu Ala Ser 2885 2890 

What is claimed is:
 1. A peptide consisting of at least 5 to less than 20 amino acids located in the region consisting of amino acids 2287 to 2306 of the HCV polyprotein of an HCV isolate which is capable of providing for immunological competition with at least one strain of HCV.
 2. A method for the detection of antibodies to hepatitis C virus present in a body fluid comprising the steps of: (a) contacting a body fluid of a person to be diagnosed with a peptide according to claim 1, and, (b) detecting an immunological complex formed between antibodies in said body fluid and said peptide as an indication of the presence of antibodies to hepatitis C virus.
 3. A kit for the detection of anti-hepatitis C virus antibodies in a body fluid, comprising: a peptide according to claim 1, and a means for detecting an immunological complex formed between said peptide and said antibodies.
 4. A peptide consisting of at least 5 to less than 20 amino acids located in the region consisting of amino acids 2299 to 2318 of the HCV polyprotein of an HCV isolate which is capable of providing for immunological competition with at least one strain of HCV.
 5. A method for the detection of antibodies to hepatitis C virus present in a body fluid comprising the steps of: (a) contacting a body fluid of a person to be diagnosed with a peptide according to claim 4, and, (b) detecting an immunological complex formed between antibodies in said body fluid and said peptide as an indication of the presence of antibodies to hepatitis C virus.
 6. A kit for the detection of anti-hepatitis C virus antibodies in a body fluid, comprising: a peptide according to claim 4, and a means for detecting an immunological complex formed between said peptide and said antibodies.
 7. A peptide consisting of at least 5 to less than 20 amino acids located in the region consisting of amino acids 2311 to 2330 of the HCV polyprotein of an HCV isolate which is capable of providing for immunological competition with at least one strain of HCV.
 8. A method for the detection of antibodies to hepatitis C virus present in a body fluid comprising the steps of: (a) contacting a body fluid of a person to be diagnosed with a peptide according to claim 7, and, (b) detecting an immunological complex formed between antibodies in said body fluid and said peptide as an indication of the presence of antibodies to hepatitis C virus.
 9. A kit for the detection of anti-hepatitis C virus antibodies in a body fluid, comprising: a peptide according to claim 7, and a means for detecting an immunological complex formed between said peptide and said antibodies.
 10. A peptide consisting of at least 5 to less than 20 amino acids of SEQ ID NO: 18, which is capable of providing for immunological competition with at least one strain of HCV.
 11. A peptide consisting of at least 5 to less than 20 amino acids of SEQ ID NO: 19, which is capable of providing for immunological competition with at least one strain of HCV.
 12. A peptide consisting of at least 5 to less than 20 amino acids of SEQ ID NO: 20, which is capable of providing for immunological competition with at least one strain of HCV. 